The present invention relates to a portable liquid crystal display device and, particularly, to a portable liquid crystal display device used for a portable liquid crystal television receiver, a portable liquid crystal monitor and the like devices. If described in further detail, the invention relates to the structure of a case such as a battery compartment cover or a stand for a portable liquid crystal display device.
Portable liquid crystal display devices for displaying image on a liquid crystal panel are light in weight, small in size, small in thickness and consume decreased amounts of electric power compared to the conventional display devices that display image on a cathode-ray tube. Because of these advantages, therefore, the portable liquid crystal display devices have, in recent years, been used in a variety of fields as multi-media equipment such as monitors, television receivers, PDAS (personal digital assistants) and the like.
In many cases, such a small portable liquid crystal display device is better watched when the image display unit is slightly tilted upward from the uprightly erected state. Therefore, the case of the portable liquid crystal display device is usually provided, on its back surface side, with a stand for standing the liquid crystal display device in a tilted state. The stand is of the swing type having a rotary shaft provided at one end thereof, and the rotary shaft is attached to a bracket provided on the back surface of the case or to a shaft hole. As required, the stand is drawn out with a swinging motion from the case, and is held in a state of being opened by a predetermined angle, so that the display device is stood in a tilted state. Furthermore, a recessed portion for holding the stand is often formed in the case on the back surface side. In such a display device, a stand that is not in use is held integrally with the case.
Batterys have been used as a power source for the portable liquid crystal display device and, hence, a battery-holding portion is formed in the case on the back surface side for holding the batterys. Usually, the battery-holding portion is covered with a battery compartment cover. At the time of renewing the batterys only, the battery compartment cover is removed from the case to open the battery-holding portion and to renew the batterys. The battery compartment cover usually slides with respect to the case.
It has been attempted to realize the portable liquid crystal display device in a small size and in a reduced weight, so that it can be easily carried. As for decreasing the size, in particular, efforts have been made to decrease the thickness as it is a tendency to increase the size of the liquid crystal display screen.
When the portable liquid crystal display device is realized in a decreased thickness, however, a problem arises in that the battery compartment cover and the stand provided in the back surface of the case interfere with each other. When there is a margin in the area on the back surface of the case, the battery compartment cover and the stand can be located on different positions in the direction of the surface as disclosed in, for example, Japanese Unexamined Utility Model Publication (Kokai) No. 63-131173. As the margin in the area on the back surface of the case decreases, however, the stand that is closed tends to overlap the battery compartment cover, making it difficult to decrease the thickness of the device.
When the liquid crystal display device is not operated for extended periods of time with the batterys loaded in the battery-holding portion, the battery-holding portion and the vicinities thereof are adversely affected by the corrosion of the batterys. When the liquid crystal display device is not used for extended periods of time, therefore, the user often removes the batterys from the battery-holding portion. However, if the user goes out carrying the liquid crystal display device with him without the batterys in the battery-holding portion, the liquid crystal display device will not work.
To prevent this, a portable liquid crystal display device has been proposed in which a window is formed in the battery compartment cover enabling the batterys in the battery-holding portion to be viewed from the external side without the need of opening the battery compartment cover (Japanese Unexamined Patent Publication (Kokai) No. 10-123488). According to this portable liquid crystal display device, furthermore, it has been attempted to decrease the thickness by overlapping the stand on the battery compartment cover.
In this portable liquid crystal display device, however, the window formed in the battery compartment cover is located at a portion where the stand and the battery compartment cover are overlapped one upon the other, and the presence of the batterys cannot be confirmed unless the stand is withdrawn from the case.
Furthermore, technology has been developed to decrease the thickness of the portable liquid crystal display device so as to approach, as much as possible, the diameter of the dry batterys which constitute the power source. This structure in which a dent is formed in the case on the back surface side thereof to hold the stand in the dent, pertains to the attempt for decreasing the thickness of the display device.
In the conventional portable liquid crystal display device, however, the battery compartment cover that slides relative to the case, as described above, makes it difficult to decrease the thickness. That is, the thickness from the outermost end surface of the stand to the side surfaces of the batterys held in the case, equals the sum of the thickness of the stand, the thickness of the battery compartment cover, and a gap to prevent an engaging hook from interfering with the batterys at the time when the battery compartment cover is slid, the engaging hook being provided on the inside of the battery compartment cover for securing the battery compartment cover to the case. This gap prevents decreasing the thickness.
Moreover, when attached to the case, the battery compartment cover may develop a play as it can be strongly depressed repetitively by finger tips during the use for extended periods of time, causing the engaging hook to be damaged or worn out, or due to dispersion in the quality of the engaging hook during the molding.
Furthermore, the above-mentioned stand is attached to the case by the rotary shafts at the ends of deflection arms formed by kerfs. When the stand is abruptly drawn out from the case or when the display device is accidentally fallen with its stand being drawn out, cracks may develop at the bottoms of the kerfs often resulting in damage.
In a practical display device, furthermore, the batterys are not, in many cases, arranged at the central portion of the display device, and the center of gravity of the device is often greatly deviated toward either the right or the left. Besides, when an antenna provided on one side on the back surface of the case of the display device is extended, the center of gravity of the display device is further greatly deviated depending upon the direction in which the antenna extends. Therefore, the position and shape of the stand attached to the case must be so contrived that the display device does not fall sideways even in the above-mentioned cases.
In the above-mentioned portable liquid crystal display device, on the other hand, a display window for viewing the image displayed on the liquid crystal panel is formed on the front surface side of the case, and a windshield (transparent dust cover) is usually arranged in the periphery of the display window to protect the liquid crystal panel. The windshield is in the form of a flat plate being made of a transparent glass or resin. The windshield is often printed to indicate display channels and the like.
In order that the windshield does not protrude beyond the case, a recessed portion is formed along the periphery of the display window for arranging the windshield, the recessed portion being lower than the surface of the case. The windshield is mounted in the recessed portion using an adhesive or a double-sided adhesive sheet, so that the surface thereof is nearly flush with the surface of the case.
According to the prior art, however, it is not possible to incorporate the windshield in the windshield-arranging portion unless the recessed portion formed in the case for arranging the windshield has a size larger than the size of the windshield. Therefore, a gap inevitably develops between the windshield that is incorporated and the case. Besides, the adhesive must be applied without break onto the periphery of the display window or the double-sided adhesive sheet must be arranged without break, so that dust and dirt will not infiltrate into the case through the gap.
Besides, in order to arrange the double-sided adhesive sheet without break around the periphery of the display window, the rectangular internal part of the double-sided adhesive sheet must be cut in a similar figure and must be removed to form a frame. The double-sided adhesive sheet of the portion that is removed is discarded, which is a waste and accounts for an increase in the cost of production.
Furthermore, when the liquid crystal display device is to be disassembled for a repair work, the windshield that is firmly secured to the recessed portion for arranging the windshield by the double-sided adhesive sheet of the shape of a frame, requires an increased amount of work and time for removal.
In order to impart high-grade feeling to the portable liquid crystal display device, furthermore, an ornamental member is often provided to emphasize color tone and touch feeling by using a member different from that of the case around the display window. However, an effective constitution has not yet been proposed for arranging the ornamental member around the display window to improve the quality of appearance of the portable liquid crystal display device and for supporting the windshield arranged around the display window on the case by using the ornamental member.
A first object of the present invention is to provide a portable liquid crystal display device in which a battery compartment cover and a stand of the swing type share the area on the back surface of the case, and the surface of the battery compartment cover is nearly in flush with the surface of the stand which is in its closed state.
The invention further provides a portable liquid crystal display device which enables the presence of batterys in the battery-holding portion provided in the back surface of the case to be viewed from the external side even in a state where the battery compartment cover remains closed.
A second object of the present invention is to provide a portable liquid crystal display device which enables the thickness of the battery compartment cover to be decreased while maintaining the strength of the battery compartment cover, eliminates the gap for preventing the interference between the engaging hook attached to the battery compartment cover and the batterys, makes it possible to decrease the thickness of the device as a whole so that it can be more easily carried, and prevents the occurrence of play between the battery compartment cover and the case caused by dispersion in the quality of the battery compartment cover during the molding.
A third object of the present invention is to provide a portable liquid crystal display device having a stand which features improved durability and maintains the portable liquid crystal display device in a state where it falls difficultly.
A fourth object of the present invention is to provide a portable liquid crystal display device having a windshield-mounting structure which does not permit dust and dirt to infiltrate onto the surface of the liquid crystal panel from the windshield provided around the periphery of the display window of the liquid crystal display device, and uses the double-sided adhesive sheet in a decreased amount for mounting the windshield on the case, contributing to decreasing the cost.
A fifth object of the present invention is to obtain a portable liquid crystal display device which exhibits improved appearance, and enables an ornamental plate to be arranged around the display window, the ornamental plate being capable of incorporating the windshield on inside thereof.
In order to accomplish the above-mentioned first object according to a first aspect of the present invention, there is provided a portable liquid crystal display device powered by batterys, comprising:
a case having, on the back surface side thereof, a battery-holding portion which is a recessed portion for holding the batterys;
a battery compartment cover of the slide type for opening and closing an opening for replacing the batterys in the battery-holding portion; and
a stand of the swing type supported by a shaft to swing relative to the case and to move between a state where it is opened by a predetermined angle with a swinging motion from the back surface of the case and a state where it is closed onto the back surface side of the case;
wherein a stand shaft support is provided in a portion of the case to support the stand in a swinging manner; and
a notch is formed in a portion of the battery compartment cover so as to be closed when the stand is closed.
With the case and the battery compartment cover being provided with recessed portions for holding the stand, the outer surface of the stand can be brought to be nearly flush with the outer surfaces of the case and the battery compartment cover when the stand is closed, and the back surface of the device can be flattened. In the state where the stand is closed, furthermore, the interior of the battery-holding portion can be viewed from the external side through the notch without the need of opening the battery compartment cover.
In order to accomplish the above-mentioned second object according to a second aspect of the present invention, there is provided a portable liquid crystal display device powered by batterys, comprising:
a case having, on the back surface side thereof, a battery-holding portion which is a recessed portion for holding the batterys;
a battery compartment cover for opening and closing an opening for replacing the batterys in the battery-holding portion; and
a stand of the swing type supported by a shaft to swing relative to the case and to move between a state where it is opened by a predetermined angle with a swinging motion from the back surface of the case and a state where it is closed onto the back surface side of the case;
wherein as engaging protrusions formed on an upper end side of the battery compartment cover are inserted in engaging holes formed in an end of the battery-holding portion of the case, the lower end of the battery compartment cover swings with the engaging protrusion as a support shaft, and the battery-holding portion is opened and closed as the battery compartment cover swings open and close.
With the battery compartment cover being allowed to swing, no wasteful gap needs be maintained between the battery compartment cover and the batterys, and the thickness of the device is decreased to improve the portability. Moreover, since the thickness of the battery compartment cover is decreased yet maintains its strength, the portability of the device is further improved. Furthermore, guides for attaching the battery compartment cover are formed on the walls by the sides of the battery-holding portion of the case, and plural pairs of engaging protrusions and engaging holes are formed in the battery compartment cover and at required portions of the case to restrict the position of the battery compartment cover. This makes it possible to prevent the occurrence of play between the battery compartment cover and the lower case caused by wear or by dispersion in the quality during the molding.
In order to accomplish the above-mentioned third object according to a third aspect of the present invention, there is provided a portable liquid crystal display device of the first and second aspects, wherein the stand is provided with deflection arms formed by kerfs, and wherein holes of approximately a circular shape larger than at least the width of the kerfs are formed at points where stress concentrates in the bottom portion of the kerfs.
In this case, the width of the stand on the side of the free end may be larger than the width of the stand on the side of an end that can be rotated. Otherwise, the free end side of the stand may be set to be asymmetrical with respect to a center line on one end side that can be rotated of the stand. Owing to this constitution, the stand is less likely to be broken, and the device becomes less likely to fall sideways in a state where the stand is drawn out.
In order to accomplish the above-mentioned fourth object according to a fourth aspect of the present invention, there is provided a portable liquid crystal display device in which a display window for viewing a display on an incorporated liquid crystal display panel is formed in a case, and a windshield is arranged in a recessed portion for arranging the windshield formed in a recessed manner in the case surrounding the display window, wherein at least one row of rib-like protuberance is continuously formed to surround the display window of the recessed portion for arranging the windshield, the protuberance protruding by a predetermined height from the recessed portion, and the back surface of the windshield comes into contact with the rib-like protuberance when the windshield is mounted on the recessed portion by a mounting means.
The mounting means may be provided on at least two places on the recessed portion on the outer side of the rib-like protuberance, on the inner side of the rib-like protuberance, or between the protuberance and the protuberance, sandwiching the display window therebetween. This prevents dust and dirt from infiltrating into the display window, and the decreased number of mounting means enables the cost to be decreased.
In order to accomplish the above-mentioned fifth object according to a fifth aspect of the present invention, there is provided a portable liquid crystal display device in which a display window for viewing a display on an incorporated liquid crystal display panel is formed in a case, and a windshield is arranged in a recessed portion for arranging the windshield formed in a recessed manner in the case surrounding the display window, wherein an ornamental member of a color tone different from the color tone of the case is arranged to surround the windshield.
The recessed portion for arranging the ornamental member in the portable liquid crystal display device can be provided in common surrounding the recessed portion for arranging the windshield, at least one row of rib-like protuberances is continuously formed in the recessed portion surrounding the display window, the rib-like protuberance protruding by a predetermined height from the recessed portion, bed plates for placing an ornamental member are formed on the recessed portion on the outer sides of the rib-like protuberance, the bed plates having a height larger than the height of the rib-like protuberance from the recessed portion but smaller than the height of from the recessed portion to the outer surface of the case, the back surface of the windshield comes into contact with the rib-like protuberance when the windshield is mounted on the recessed portion by the mounting means, and the ornamental member is mounted on the bed plates by the mounting means.
Furthermore, a first inclined surface inclined toward the bottom surface of the recessed portion of the case is formed along at least one edge of the recessed portion, a second inclined surface opposed to the first inclined surface is formed on a portion opposed to the first inclined surface of the back surface of the ornamental member near the outer periphery thereof, and the ornamental member is mounted on the recessed portion in a state where the second inclined surface of the ornamental member is overlapped on the first inclined surface. Owing to this constitution, no conspicuous gap appears between the case and the ornamental member.
In this case, a visor portion is formed at the edge on the outer peripheral side of the second inclined surface of the ornamental member so as to slightly protrude outward from the second inclined surface, and is overlapped on the outer surface near the recessed portion of the case at the time when the ornamental member is mounted on the case. Thus, a step between the ornamental member and the case becomes less conspicuous.